High voltage power circuit breakers today are generally grouped into two classes: live tank and dead tank designs. A dead tank circuit interrupter generally is one in which the interrupting unit, with its separating contacts, is disposed within an electrically grounded metal tank which then is disposed on or at physical ground level. A live tank design, on the other hand, has its interrupting unit, with its separating contacts, disposed in an insulating tube which then is supported upon an insulating column.
The interrupting unit of a live tank circuit breaker usually consists of an insulating rod which is disposed in the insulator tube of the live tank circuit breaker and configured to be movable in a direction parallel to the longitudinal direction of the insulator tube. Also, the insulating rod needs to be centered inside the insulator tube, and/or supported to avoid buckling, which usually is accomplished by having the insulator tube provided with support brackets fixed to its inside surface. The support brackets in question are usually ring-shaped and their outer circular surfaces have to be attached to the inside surface of the insulator tube, and their inside surface configured to support the insulating rod. Earlier a support bracket for the above-mentioned purpose consisted of a solid ring which was fixed to the inside of the insulator tube by means of an adhesive joint.